Motorized vehicle suspension systems have been using leaf springs for over a 100 years. Before motorized vehicles, horse drawn carriages often utilized a leaf spring suspension system. Thus, there has existed a long felt need for a connection assembly for coupling an end of a leaf spring to a vehicle that is reliable, inexpensive, and includes only a few parts.
A previously developed connection assembly 100 attempting to satisfy this long felt need is depicted in FIG. 1. Referring to FIG. 1, a leaf spring 102 is depicted having a spring eye 104. A pin 106 is disposed through the spring eye 104. The ends of the pin 106 are coupled to a frame 108 of the vehicle (not shown). The frame 108 includes two saddles 110 for partially receiving each of the ends of the pin 106. The ends of the pin 106 are held in the saddles 110 by a pair of caps 112 which clamp the ends of the pin 106 within the saddles 110. Each of the caps 112 is bolted to the frame 108 through a pair of bolts 114, a pair of nuts 116, and a pair of washers 118.
Although somewhat effective, this previously developed connection assembly 100 is not without its problems. For instance, to couple the pin 106 to the frame 108, a pair of bolts 114, nuts 116, and washers 118, and a cap 112, must be manufactured to hold each end of the pin 106 within one of the saddles 110. Thus, to couple the pin 106 to the frame 108, fourteen parts (4 bolts, 4 nuts, 4 washers, and 2 end caps) must be manufactured, increasing the complexity and cost of the connection assembly 100.
Further, the pin 106 is a smooth cylindrical structure. Although relatively inexpensive to manufacture, if the clamping action of the cap 112 is less than optimum, there is a risk that the smooth pin 106 could axially work its way out of the spring eye 104.
Further, the caps 112 are expensive to manufacture since they must be both strong and made to close tolerances, further increasing the cost of the connection assembly 100. Further still, it has been found that the caps 112 often deform when stressed, decreasing the holding power of the cap 112 upon the pin 106, thereby increasing the risk of the pin 106 working loose. Further, since the bolts 114 and nuts 116 don't directly engage the pin 106, the tightness of the bolts 114 and nuts 116 does not always directly relate to the tension applied to the pin 106. For instance, even though the bolts 114 and nuts 116 are fully tightened, the full force of the bolts 114 and nuts 116 are not exhibited directly upon the pivot pin 106, thus making it possible for the pivot pin 106 to work loose when the caps 112 deform under load.
Thus, there exists a need for a connection assembly for coupling a leaf spring to a vehicle that is reliable, inexpensive to manufacture, and which has a reduced number of parts.